This invention relates to a contact pressure detecting sensor and a contact pressure measuring device including the same, and more particularly to a contact pressure detecting sensor for measuring a contact pressure occurring between each of parts or regions of the body of a patient or the like in bed and bedding and a contact pressure measuring device having such a contact pressure detecting sensor incorporated therein.
In recent years, in a nursing or caregiving field such as a home, a hospital or the like, nursing or care for bedridden patients keeps on increasing with an increase in aged people. In such a field, patients are typically subject to continuous pressure over a long period of time, to thereby be exposed to a danger of bedsore. An idea that such pressure is reduced to prevent occurrence of the bedsore leads to commercial development of a variety of bedsore prevention instruments such as an air mattress and the like in the world.
Separately from such an approach as described above, a variety of contact pressure measuring devices have been developed which are adapted to measure a magnitude of a pressure actually applied to each of parts of the body of a patient. One of the contact pressure measuring devices is constructed so as to arrange a number of sensors all over a bed, so that signals outputted from the sensors are analyzed through a computer to display a pressure distribution while classifying the pressures by color. Such a contact pressure measuring device is typically used for researches and made to order, resulting in being highly expensive and large-sized. Also, operation of the contact pressure measuring device requires high-grade knowledge and skill.
Thus, currently it is substantially impossible in an actual nursing or caregiving field to detailedly know conditions which cause a surface of the body of a patient in bed to be subject to pressure, as well as a degree of improvement in a pressure environment by employment of a bedsore preventing equipment. Therefore, nursing or caregiving staff substantially fails to know a danger of occurrence of bedsore in a patient due to a pressure which is inherently unobservable, leading to occurrence or worsening of bedsore which would be able to be necessarily prevented.
Recently, a relatively small-sized contact pressure measuring device unlike the large-sized device described above is developed. The small-sized contact pressure measuring device includes such a contact pressure sensor as indicated at reference numeral 40 in FIGS. 5A and 5B. The contact pressure sensor 40 is so constructed that two films 40a are laminated on each other so as to define a hollow section 40b therebetween and a tube 40c is arranged in a manner to be drawn out of the hollow section 40b. Then, a coupler 40d is mounted on a distal end of the tube 40c.
In operation of the contact pressure sensor 40 thus constructed, a predetermined amount of air is injected into the hollow section 40b. Injection of air is carried out through the coupler 40d provided therein with a check valve (not shown) by means of an exclusive or dedicated air cylinder (not shown). Thus, the check valve prevents air in the hollow section 40b from leaking out of the hollow section 40b after the air cylinder is detached from the sensor 40 following injection of air. Then, the coupler 40d is fitted in a socket of a body of the contact pressure measuring device. This permits opening of the check valve of the coupler 40d, so that a pressure of air in the hollow section 40b of the contact pressure sensor 40 may be applied to a pressure detector arranged in the body of the measuring device. A pressure applied to the pressure detector is varied depending on a pressure applied to the contact pressure sensor 40, so that a signal outputted from the pressure detector is subjected to electrical processing for display.
Unfortunately, in the conventional contact pressure measuring device, operation of injecting air into the hollow section 40b by the air cylinder is highly troublesome. Also, the air cylinder and the coupler of the contact pressure sensor are complicated in structure, to thereby fail to reduce the cost. Such complication of the structure often leads to further disadvantages such as leakage of air and the like.